The function of the blood-brain barrier (BBB) depends on the integrity of tight junction (TJ)-associated proteins. Netrin-1 is known to promote angiogenesis and may also regulate the BBB. To understand the association between netrin-1 and the TJ-associated proteins, the expression levels of proteins involved in maintaining the integrity of the BBB, including netrin-1, claudin-5, occludin and zonula occluden (ZO)-1, were investigated in the present study using quantitative polymerase chain reaction, western blot analysis and immunofluorescence. The aim of the present study was to determine the changes in BBB permeability and whether pZsGreen1-N1 mediated overexpression of netrin-1 increased the expression of the TJ-associated proteins following traumatic brain injury (TBI). The results demonstrated that the levels of mRNA transcription and protein expression of the TJ-associated proteins, claudin-5, occludin and ZO-1, were significantly reduced following TBI. Furthermore, the changes in the expression of these three TJ proteins were consistent with the changes in the BBB permeability, indicating that weakening intercellular junctions leads to BBB opening. The present study also demonstrated that netrin-1 significantly increased the downregulation of claudin-5, occludin and ZO-1 expression levels induced by TBI, which provided a basis for further investigation on the role of netrin-1 in the integrity of TJs and proper functioning of the BBB.
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BACKGROUND: At present, the salvage treatment has become the standard method for the treatment of limbs malignant bone tumor, and the purpose of the surgery is not only to improve the survival rate, but also to save the good limb function. OBJECTIVE: To review several salvage treatments, such as artificial joint replacement and allograft bone graft for the treatment of limbs malignant bone tumor. METHODS: The PubMed database from January 1992 to October 2012 and China National Knowledge Infrastructure database from January 1994 to December 2012 were searched by the first author for the articles on the treatment of malignant bone tumor with salvage treatment with the key words of "malignant bone tumor, salvage treatment, allograft bone graft, prosthesis and microwave" in English and Chinese. The repetitive articles and the Meta analysis were eliminated, and finally, a total of 31 articles were included for the review. RESULTS AND CONCLUSION: For the malignant bone tumor on limbs, especially around the joint, the artificial joint replacement, allograft bone graft and microwave inactivation treatment were the main methods. The allograft bone graft has a high complication incidence, and the microwave inactivation has new progress. The new progress needs further research. Tumor segment devitalization and replantation and alcoholic devitalization and replantation are more applicable to the primary hospital.
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